Disposable laryngeal mask airway (Soft Seal) for endotracheal intubation: FOB guidance technique and blind technique.

OBJECTIVE: To evaluate disposable LMA for endotracheal intubation using the FOB guidance and blind techniques.

MATERIAL AND METHOD: The authors included ASA class I-II patients between 15 and 60 years of age, with mouth opening more than 3 cm, scheduled for elective surgery. The authors excluded patients with any history of gastro-esophageal reflux, full stomach or a body weight < 30 kg. All of the patients received standard general anesthesia. After inducing anesthesia, a disposable LMA No. 3 or No. 4 (Soft Seal, Smiths Medical, Portex Inc, USA) was inserted while the patient was in the sniff position. The authors recorded the insertion time, the ease of insertion, the anatomic placement and position. The authors then inserted a flexible endotracheal tube (No. 6.5 for LMA No. 4 and No. 6 for LMA No. 3) and recorded the success rate and the ease of insertion. After three failures, the authors used FOB guidance.

RESULTS: Sixty patients were enrolled (32 males). The mean +/- SD age and BMI was 43.2 +/- 13.4 years and 22.6 +/- 3.9, respectively. Most of the patients had a Mallampati of grade I. The mean +/- SD insertion time was 24.6 +/- 16.1 sec. After the FOB evaluation, only 27 patients had an anatomic placement in full view of the glottis. Eighteen patients had vocal cords in the middle part of the opening. The success rate of blind endotracheal intubation was 5 percent (95%CI 1.0-13.9) (3/60); while the success rate with FOB guidance was 85 percent (95%CI 73.4-92.9).

CONCLUSION: A disposable laryngeal mask airway (Soft Seal) for blind endotracheal intubation had a low success rate, but it could be used more successfully with FOB guidance.